Replication data for: Effects of irradiance and temperature on growth and yield in potato cv. Gullauge

Both light intensity and temperature are key factors for photosynthesis and growth in crop plants. Especially in marginal climate conditions, such as at high latitudes in low solar elevations and low temperature. The influence of irradiance and temperature on development, growth and yield was investigated in the Scandinavian potato cultivar Gullauge in phytotron. Pre-sprouted seed tubers in two separate seasons were grown to harvest at four irradiance levels between 80–215 µmol/m2/s, and at constant temperatures: 18 °C in 2020, and 9, 15 and 21 °C in 2021. Temperature affected more responses than light intensity, having a positive effect on shoot biomass and plant height, and a negative effect on vegetative development time and number of shoots. Tuber yield and dry matter content plateaued at or were highest at the intermediate temperature 15 °C. Irradiance principally reduced development time, plant height and increased tuber yield and dry matter content, all under a strong interaction with temperature. Here the effects for low-temperature delay in development and temperature-induced increase in plant height, were most pronounced as irradiance decreased. The effectiveness of irradiance levels for tuber yield and dry matter content decreased more at the lowest temperature 9 °C compared to at the higher temperatures. The results indicate that high irradiance levels become increasingly important for potato growth at low temperatures. Midnight Sun with very long daily photosynthesis periods is thus key for potato production at high latitudes. In a future warmer climate, the alleviated light requirements may improve production here.